1. For the dough:
2. Preheat the oven to 375 degrees F. Prepare a cookie sheet by lining it with either a silpat (nonstick baking mat) or a piece of parchment paper.
3. Cut the butter into about tablespoon size pieces, then place in the freezer while you prepare the dry ingredients.
4. In a large bowl, combine the 4 cups all purpose flour, baking powder, baking soda, and salt. Scatter the butter pieces over the top, then cut in the butter using a pastry cutter or two butter knives until the mixture resembles a coarse meal. The butter does not need to be uniform but most of the pieces should be the size of small peas. Pour the buttermilk over the top and gently mix with a fork or wooden spoon until the mixture just begins to come together. If the dough seems overly dry, add 1 additional tablespoon of buttermilk. It should be moist, but not sticky.
5. Scrape the dough onto a lightly floured work surface and pat it flat. Lightly flour the top of the dough and using a rolling pin, roll the dough into a 16 x 12-inch rectangle that is about 1/4-inch thick.

For the filling: Spread the surface of the dough with the 4 tablespoons softened butter. In a small bowl, stir together the brown sugar, and cinnamon. Scatter the mixture evenly over the butter, leaving a 1/2-inch border on all sides.

1. Starting with the short (12-inch) side, roll the dough up tightly into a log, patting it as you go to help seal it. Trim 1/4-inch of dough off of each end so that they are even. With a very sharp knife, cut the log into 8 equal pieces. Arrange the rolls in the prepared baking dish, spacing them evenly (they will expand when baked). Bake until puffed, and golden brown, about 25 to 35 minutes.

Glaze:

1. While the rolls bake, prepare the glaze: in a small bowl, whisk together the powdered sugar, melted butter, vanilla extract, and cream or milk. If you desire a thinner glaze, add a little more milk, until your desired consistency is reached. Drizzle over the warm rolls and enjoy!

Notes:

1. These are best eaten the day they are made, but can be kept at room temperature for a day. Reheat in microwave.
2. Make them ahead: The biscuit dough can be prepared through Step 3 up to 1 day in advance. Store it in the refrigerator, then when you are ready to bake, start at Step 4 (rolling the dough), then bake as directed.
3. You could also form the rolls all the way up until they go in the oven and store them in the refrigerator in the baking pan for a few hours. Let the rolls stand at room temperature for about 10 minutes, then bake as directed.